This Bumbleride wheel replacement is compatible with 2019-2020 Era strollers. Inner tube inside is 12" x 1.75" (30 x 4 cm). If your wheel is flat, you may need a 12-inch jogging stroller inner tube replacement or more air. Make sure not to over inflate, we recommend 25-30 psi (foot or hand pump recommended). If replacing inner tube yourself, make sure to use a tire lever or two to help.